yea i would start building his cage pretty soon as he has the potential to be 4ft long in a year and very well should be, these guys grow like lightning, a friend of mine has 7 6 month old black throat monitors that are all over 4 feet, and he admits to not feeding them all that much
skip the bin you will lose too much humidity build a 4x2x3 with a foot of dirt and a basking spot of 120+ and then start working on that 4x8 cage
they need a lot of dirt and just that plain old dirt that you dig up mixed with a bit of sand until you have 1/3 ratio of sand to dirt and please think of this for a while and don't impulse buy it, these guys get big, have you ever handled a large monitor one that will likely bite and hiss and tail whip you
a bite from a four foot lizard is a very painful one
I was bitten by a 3 foot iguana and I still have a few scars from it, so please take this into consideration when i say they are NOT beginner animals
skip the bin you will lose too much humidity build a 4x2x3 with a foot of dirt and a basking spot of 120+ and then start working on that 4x8 cage
they need a lot of dirt and just that plain old dirt that you dig up mixed with a bit of sand until you have 1/3 ratio of sand to dirt and please think of this for a while and don't impulse buy it, these guys get big, have you ever handled a large monitor one that will likely bite and hiss and tail whip you
a bite from a four foot lizard is a very painful one
I was bitten by a 3 foot iguana and I still have a few scars from it, so please take this into consideration when i say they are NOT beginner animals